Valentina Tanduo

Spider crabs of the genus Eurynome have complex taxonomic, phylogenetic, and biogeographic histories worldwide. Using newly generated molecular data, including the characterization of complete mitochondrial genomes, we addressed several unresolved questions surrounding the genus and its two Atlantic‐Mediterranean representatives, the type species Eurynome aspera and its sympatric Eurynome spinosa . DNA‐barcoding and reverse taxonomy demonstrated conspecificity between Atlantic and Mediterranean samples, confirmed the occurrence of E. spinosa in the Mediterranean Sea sensu stricto , and contradicted most diagnostic characters previously proposed in the literature. In their place, a set of 10 molecularly validated morphological traits, regardless of sex and developmental stage, was proposed and accompanied by high‐resolution imagery. The DNA‐assayed material was then used to investigate the phylogenetic position of Eurynome through various inferences (multilocus and mitochondrial genome trees, and mitochondrial gene orders), which suggested that these taxa form a distinct, early‐diverging clade, for which the family Eurynomidae Neumann, 1878 is resurrected here. This was also supported by high similarity with the ancestral Brachyura mitochondrial gene order and strong dissimilarities with other majoid ones. Although several questions remain open, the present results resolve debates on two pseudo‐cryptic species, elevate Eurynome to one of the most molecularly characterized majoid genera, and lay a solid foundation for proceeding with the study of allied taxa and the entire superfamily through modern integrative approaches.

The Mediterranean Sea is one of the major reservoirs of marine biodiversity and harbors an exceptionally high number of endemic species. Nevertheless, the taxonomic status of many of these endemics still requires confirmation through integrative, modern approaches. We hereby first investigated the identity and status of a rare and endemic box crab, known either as Calappa rosea or Calappa rissoana , through a multidisciplinary approach that capitalized on the use of nomenclatural rules, museology, integrative taxonomic approaches (morphology, complete mitochondrial genomes, nuclear markers, and phylogenetic analyses), and passive citizen science. Almost all morphological characters failed to differentiate it from the related species Calappa granulata , whereas differences in coloration were mostly confirmed here. However, all molecular approaches supported the conspecificity of these two taxa. The combined use of passive citizen science and statistical analyses revealed that the formerly endemic species is an unrecognized ontogenetic stage of C. granulata , and, in particular, a rare transitional phase that connects early juveniles to fully developed adults. This renders the investigated taxon a new junior synonym of C. granulata and solves nomenclatural and taxonomic ambiguities related to native Mediterranean box crabs, which have remained unsettled for over 200 years. The present study, therefore, provides the first comprehensive reconstruction of the ontogenetic changes occurring in the common Mediterranean box crab throughout its various life stages and raises questions on whether these transitions occur worldwide across box crabs or are restricted to a few species. Finally, it presents new, conspicuous, and detailed morphological and molecular data on the type species of the genus Calappa , facilitating future phylogenetic reconstructions and taxonomic assignments within the entire family Calappidae, and discusses the putative occurrence of the other box crabs in the area, suggesting a critical re‐evaluation of all historical data and records.

Biological invasions threaten biodiversity worldwide. The American blue crab Callinectes sapidus Rathbun, 1896, among the Mediterranean’s most damaging invaders, takes up the challenge to transform this threat into gain. To turn its impact into economic value and guide control efforts, we analysed separately the meat composition and exoskeleton biopolymers of adult crabs from three Moroccan protected Sites of Biological and Ecological Interest: Marchica Lagoon (S₁), Moulouya Estuary (S₂), and Al Hoceima National Park (S₃). Marchica specimens exhibited the highest protein content (21.87 ± 1.15 g 100 g⁻¹, p < 0.001) and an elevated lipid fraction, yielding nutrient-dense meat suitable for premium markets. Moulouya crabs were noted for their taste potential, with a higher concentration of fat (1.73 ± 0.09%) and carbohydrates (0.91 ± 0.1%). Al Hoceima individuals displayed markedly mineralised exoskeletons producing lean and low-fat meat, valued in dietary applications. Exoskeleton organic-to-mineral (OM/MM) ratios and proximate composition revealed three adaptive profiles, opportunistic (S₁), acclimatory (S₂), and conservative (S₃), presumably correlated to local salinity, productivity, and substrate conditions, underscoring the species’ phenotypic plasticity. X-ray diffraction confirmed the α-chitin polymorph, while FTIR analysis indicated degrees of deacetylation consistent with high-purity chitosan. These findings support the development of a site-specific circular economy framework and may contribute to the ecological resilience of Morocco’s protected coastal areas.

The genusLysmataRisso, 1816 includes five species in the Mediterranean Sea, namely two well-known species with an Atlantic–Mediterranean distribution,L. seticaudata(Risso, 1816) andL. nilitaDohrn & Holthuis, 1950, and three additional species only known from single records. These areL. kempiChace, 1997 andL. vittata(Stimpson, 1860), alien species native to the Indo-Pacific region, andL. olavoiFransen, 1991, a poorly known species originally described from the Azores (Atlantic Ocean) and only reported three decades ago from the eastern parts of the basin. Based on an integrative taxonomic approach, we report the first finding of an ovigerous female ofL. olavoifrom Italy (Gulf of Naples, Tyrrhenian Sea) and the entire western Mediterranean, thus confirming the presence of this species in the basin and filling a wide gap in its published distribution. It is possible that this taxon was present in the Mediterranean for centuries but went overlooked or undetected due to cryptic habits, occupancy of still unexplored habitats, or misidentification with the highly similarL. seticaudata. Results of phylogenetic analyses confirm the exclusion ofL. olavoiby the major lysmatid groups and underline the necessity of multilocus approaches to disentangle its correct phylogenetic position. As the species is still surrounded by a number of unsolved ecological and phylogenetic questions, further field and laboratory work is required to shed light on them.

Natural products and their synthetic analogs and derivatives are a traditional source of bioactive molecules with potential development as drug candidates. In this context, Marine Natural Products (MNPs) represent a rich reservoir of diverse molecular skeletons with potential pharmacological activity that, so far, has been mostly explored in cancer and infectious diseases. Starting from the development of a novel bioassay-guided screening platform for immunomodulatory compounds from an in-house MNPs library, we report the identification of the alkaloid lepadin A as a new model compound for immune-based anticancer activity with characteristics that suggest a possible mechanism as Immunogenic Cell Death inducer. The work describes the molecular-based bioprospecting in the Gulf of Naples together with the bioassay-guided fractionation, the chemical characterization of the alkaloid, and the biological activity in mouse dendritic cells (D1).

Camouflage is the method by which animals conceal by blending in with the environment, and may be achieved by fixed or changing color, shape, texture, chemical secretions, and/or behavior

Scyllarus Fabricius, 1775 includes nine species worldwide, three of which have been recorded from the Mediterranean Sea: S. arctus ( Linnaeus, 1758), S. caparti Holthuis, 1952, and S. pygmaeus Bate, 1888. A Scyllarus specimen not ascribable to any of the previous species was trawled in November 2020 in unconsolidated substrates in the Gulf of Naples, Italy. The sample was subsequently identified through an integrative taxonomic approach as Scyllarus subarctus Crosnier, 1970, a species originally described from southern Angola (Eastern Atlantic Ocean) and apparently expanding northward along Western Africa. It is possible that this taxon may have been already present in the Mediterranean but went overlooked or undetected. Results obtained through molecular analyses underlined the necessity of an extensive update of the supraspecific taxonomy of scyllarids.

Biological invasions constitute a major threat to native ecosystems and to global biodiversity